Although there are many technologies for liquid phase protein quantification, most of these technologies can only detect a single indicator in a sample. When detecting multiple indicators simultaneously, a large number of samples are required for batch testing, which is cumbersome and the differences between various indicators are significant. For users with a small number of samples or those who need to compare various indicators, traditional technologies cannot meet the requirements. Moreover, in routine experiments, it is often necessary to quantitatively detect soluble proteins in solution systems, such as the quantitative analysis of cytokine content in cell culture supernatant or serum. Due to the low content of these factors, which is below the detection limit of general conventional methods, it is difficult to detect using conventional protein detection methods like Western Blot. Absin provides CBA (Cytometric Bead Array) multi-factor detection kits, offering a more flexible, convenient, and efficient solution for the detection of multiple indicators in small samples.

Principle:

Specific antibodies are conjugated to microspheres with distinct fluorescence intensities to prepare capture microspheres for the target analytes (Capture Antibody). The capture microspheres are incubated with the test samples (serum, plasma, or cell culture supernatant), during which the target cytokines are captured by the specific microspheres. Biotin-labeled detection antibodies form an immunocomplex of antibody-coated microspheres-cytokine-detection antibody. Phycoerythrin-labeled streptavidin binds to the biotin, and the fluorescence intensity is detected by a flow cytometer. The fluorescence intensity is proportional to the amount of the analyte in the sample. Finally, by combining with the standard curves of these twelve cytokine standards, it is possible to quantitatively detect multiple analytes in the same sample, aiding in the assessment of the immune function status of the organism.

Sensitivity of Detection for Different Indicators：

Note: If the test results are outside the detection range, the sample should be diluted appropriately with standard/dilution buffer and retested; if the test results of the sample are below the lower limit of detection or not detected, it is recommended to report it as ≤ the lowest detectable value.

Method for Establishing the Template:

1、Distribution of Microsphere Populations:

Note: The microspheres are stained with different intensities of fluorescent dyes inside.

2、Template Establishment: The template can be established by referring to:
(1) Create a density plot template with FSC-H on the X-axis and FSC-A on the Y-axis, set gates to exclude debris and clumped microspheres, as shown in Figure 1, P6; (2) Create a linear density plot template with FSC-H on the X-axis and SSC-H on the Y-axis, set the positions of mixed microspheres R1, R2, R3, as shown in Figure 2; (3) It is recommended to create two log density plot templates for PE (on the X-axis) and APC (on the Y-axis), respectively displaying the microspheres within gates R1, R2, R3, so that the microsphere populations can be clearly and distinctly distributed on the scatter plot, showing the PE fluorescence intensity of each factor. As shown in Figures 3, 4, and 5.

3、Analysis of Sample Test Results

Each standard and sample is tested sequentially, and for each microsphere population, at least 100 microspheres should be obtained. Use the standard gradient to make a standard curve and calculate the sample test results.

Applications of CBA：

• Analysis of the levels of inflammatory factors.
• Tumor research and auxiliary diagnosis of tumor diseases, monitoring of therapeutic efficacy, and prognosis.
• Monitoring of immune diseases such as systemic lupus erythematosus (SLE) and neonatal sepsis.
• Research and monitoring of stem cell therapy.
• Immunological research and auxiliary diagnosis and monitoring of immune diseases.
• Research on infectious diseases and auxiliary diagnosis and evaluation of therapeutic efficacy.
• Monitoring of immune function.
• Evaluation of drug efficacy, drug development, and vaccine research.

Advantages of CBA compared to traditional protein quantification:

Advantages of Absin CBA kits:

Combinations of multi-factor detection kits available:

Absin's existing kits

Accessories

On the basis of the existing indicators in the kit, you can choose to combine individual indicators to form a kit with fewer indicators (such as four or five cytokines), but the indicators for humans and mice are not interchangeable. You can contact our sales staff to inquire about the pricing and delivery time of the customized kit.

Absin provides antibodies, proteins, ELISA kits, cell culture, detection kits, and other research reagents. If you have any product needs, please contact us.

Absin Bioscience Inc. Email: worldwide@absin.net

Follow us on Facebook: Absin Bio